Amana AMSS920803BN Error Code 5 Flashes: Flame Sensed With No Call for Heat
What Does Code 5 Flashes Mean?
Five flashes on the Amana AMSS920803BN mean the Integrated Control Module is sensing flame current when the furnace is idle and no heat has been requested. When there is no call for heat there should be no flame and therefore no flame-sense current, so the board treats an unexpected signal as a fault and responds protectively — it runs both the induced-draft blower and the circulating blower continuously to purge the system.
On this model the flame sensor works by passing a small microamp current through the flame to ground. The manual attributes a false flame-with-no-call reading to a short to ground in the flame-sense circuit: a pinched or chafed sensor wire, moisture, or a cracked ceramic insulator letting the rod contact metal can all feed the board a signal that imitates a real flame.
This code shares the flame-sense circuit with seven flashes (code-7, low flame signal), but the two are opposites. Five flashes is a false positive while the furnace is at rest; seven flashes is a genuinely weak signal while the burner is firing. Because five flashes involves the flame-safety circuit, this model classifies it for professional repair — turn the furnace off at the switch until it is corrected.
What You'll Notice
- The inducer and the indoor blower run non-stop even with no call for heat
- The single diagnostic LED blinks five times, pauses, and repeats
- The furnace will not run a normal heating cycle
- The fans keep running even after the thermostat is satisfied or switched off
- You may find a chafed, pinched, or wet flame-sensor wire near the burners
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Short to ground in flame sensor wiring | Most common | ✗ Call a pro → |
How This Is Diagnosed
With power off, a technician inspects the flame-sensor rod and its wire for a short to ground — checking for chafing where the wire crosses metal, a cracked porcelain insulator, or moisture intrusion. They test the flame-sense circuit for continuity to ground, then repair or replace the affected wire or sensor. The control module is checked last, only after the wiring and sensor have been cleared, since a circuit short is the far more common cause.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The blower and inducer run continuously and will not shut off
- Five flashes persist after cycling power to the furnace
- You can see a chafed, pinched, or melted flame-sensor wire
- The fans keep running even with the thermostat turned off
Frequently Asked Questions
Why won't the fans shut off?
The board runs them on purpose when it senses flame with no heat call, to safely clear any combustion products. It is a protective response to the fault, not a stuck fan or relay.
Is a false flame signal dangerous?
The condition itself is usually a wiring short, but because it involves the flame-safety circuit it should be repaired promptly by a technician. Turn the furnace off at the switch until then.
Can I fix the flame-sense wiring myself?
No. This is low-voltage safety-circuit work classified for a professional, who will locate the short to ground and repair it correctly so the safety function is restored.
Sources
✓ Verified against manufacturer service manual — March 2026